JP2006016887A - Turning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turning device capable of automatically supplying grease to a rolling body storage section between an inner wheel and an outer wheel from a grease bath to eliminate impurities mixed in grease. <P>SOLUTION: Circular gaps 13a and 13b are formed in up and down of the rolling body storage section 13 formed between the inner wheel 11 and the outer wheel 12, the circular gap 13b on the lower part side is sealed with a lip-like sealing member 28, the circumferential surface of the inner wheel 11 and the inner circumferential surface of the outer wheel 12 become tapered surfaces 11a and 12a notched in the diagonal direction toward the upper end section for the circular gap 13a on the upper part side, a plastic grease 30 is fixed in the circular gap 13a by a holding plate 31, and grease is automatically supplied to the rolling body storage section 13 by the plastic grease 30 in the case the turning device 3 is operated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a turning device provided to connect an upper structure to a lower structure such as a construction machine so as to be capable of turning.

  Construction machines such as hydraulic excavators, cranes, and wheel excavators have a crawler-type or wheel-type lower traveling body as traveling means, and an upper revolving body is installed on the lower traveling body via a revolving device. And an operation means, a driver's cab, etc. will be installed in a revolving super structure. A turning device that connects the lower traveling body and the upper turning body so as to be turnable includes a turning bearing and a turning drive means. The slewing bearing has an inner ring and an outer ring, and a rolling element housing portion is formed between the inner ring and the outer ring, and a predetermined number of rolling elements made of steel balls are mounted in the rolling element housing portion. At the same time, a spacer is interposed between adjacent rolling elements to position each rolling element. Usually, the inner ring is connected to the lower traveling body, and the outer ring is connected to the upper turning body. As a turning drive means, a ring gear is formed on the inner surface of the inner ring, and a turning pinion is attached to the output shaft of a turning motor provided on the upper turning body. It meshes with the inner ring gear.

  Accordingly, when the turning motor is driven, the turning pinion meshed with the ring gear rotates, so that the outer ring connected to the upper turning body rotates relative to the inner ring connected to the lower traveling body. become. In order to minimize friction at the time of relative rotation between the outer ring and the inner ring, a rolling element is interposed between the outer ring and the inner ring. In order to further smoothly rotate the rolling element, For example, grease is sealed as a lubricant. In addition, the rolling element housing portion has a space for accommodating the rolling elements, but the upper and lower portions thereof are formed with a narrow gap between the inner ring and the outer ring, so that the inner ring and the outer ring do not slide in contact during turning. I am doing so. Accordingly, since the upper and lower ends of the rolling element housing portion are open, in order to keep the enclosed grease from leaking to the outside, the seal member is mounted so as to span between the inner ring and the outer ring. ing. Normally, the seal member is mounted on the upper and lower sides of the rolling element housing portion, whereby the rolling body housing portion is closed.

  Here, one end side of the seal member is fixed to either the inner ring or the outer ring, but the other end portion is in sliding contact with the other party, so that complete sealing cannot be achieved. For this reason, the grease in the rolling element housing portion decreases due to seal leakage or the like over a long period of time. For this reason, in the past, grease was supplied to the rolling element housing part regularly or at any time. However, since this greasing work is troublesome, in order to eliminate the need for grease for a long period of time. Conventionally, grease that is automatically replenished is known.

  Here, in order to lubricate between the ring gear provided on the inner ring and the turning pinion, an annular grease bath is provided inside the inner ring, and when the turning pinion rotates, the grease in the grease bath is removed. It will be fried. Therefore, a configuration using the grease in the grease bath as a replenishment source has been conventionally known. For this purpose, the upper part between the inner ring and the outer ring is not provided with a seal member, and the gap on the upper part is opened, so that the grease swept up by the operation of the turning pinion is transferred from the gap. It is comprised so that it may guide in a moving body accommodating part.

Further, Patent Document 1 discloses a configuration in which plastic grease is attached to a spacer provided in a rolling element housing portion in order to supply fresh grease as well as replenishing grease from a grease bath. Yes. Plastic grease is a resin material such as polyethylene that is heated above its melting temperature. After mixing this resin material and grease, it is cooled to room temperature and solidified to a predetermined shape. It is a thing. In this plastic grease, liquid grease is dispersed in the solidified resin. Accordingly, when the plastic grease is compressed and deformed, fresh grease held in the resin oozes out, and when the compression is released, the grease existing in the surrounding area is absorbed.
JP 2002-173951 A

  When configured as in Patent Document 1, not only grease is supplied from the grease bath, but also fresh grease can be supplied from plastic grease, and grease with good sliding conditions can be obtained without troublesome lubrication. Since the slewing bearing is supplied, it has an excellent effect that the slewing bearing can be operated smoothly over a long period of time. However, the configuration of Patent Document 1 is not without problems.

  That is, fresh grease is supplied from plastic grease as a grease supply source to the rolling element housing portion, but there is a possibility that impurities are mixed in grease replenished from the grease bath. That is, although the grease bath is substantially kept in a sealed state, condensation may occur due to a temperature difference between the inside and outside of the wall surface defining the grease bath, and moisture may be mixed into the grease in the grease bath. . In addition, the grease bath is provided between the lower traveling body side and the upper swing body, that is, the wall that seals the grease bath is composed of a member that constitutes the lower traveling body and a member that constitutes the upper swing body that rotate relative to each other. In addition, since the center joint is provided so as to penetrate vertically through the center of the grease bath formed in an annular shape, the grease bath cannot be completely sealed. In particular, since construction machines operate in the field, it is not possible to completely prevent rainwater or dust from entering the grease bath. Further, the grease in the grease bath is for lubricating the meshing portion of the ring gear and the swivel pinion, and there is a possibility that abrasion powder is generated in this meshing portion.

  Therefore, using the grease in the grease bath as a replenishment source for the rolling element housing is not desirable in that the contaminated grease may be replenished. However, if the grease supply to the rolling element housing is limited to plastic grease and is not supplied from the grease bath, the reduction due to grease that leaks during operation cannot be compensated for. Will have to be done.

  The present invention has been made in view of the above points, and an object of the present invention is to mix grease into the rolling element housing portion between the inner ring and the outer ring from the grease bath. It is to be able to remove impurities to be removed.

  In order to achieve the above-described object, the present invention forms an annular rolling element accommodating portion between an inner ring and an outer ring, and a predetermined number of rolling elements and spacers are alternately arranged in the rolling element accommodating portion. And a turning device having a turning bearing in which a lubricant is enclosed, and an annular seal member that seals the lower part of the rolling element housing portion is attached to the lower side between the inner ring and the outer ring, It is characterized in that an annular plastic grease is mounted on the upper side.

  An annular gap is formed above and below the rolling element housing portion formed between the inner ring and the outer ring, and grease is automatically replenished from the upper gap. Plastic grease is attached to the gap on the upper side, and fresh grease is held in this plastic grease. Since the gap between the inner ring and the outer ring changes during operation of the turning device, the plastic grease is compressed and deformed. For this purpose, fresh grease held in the plastic grease is supplied to the rolling element housing portion.

  When the inner ring and outer ring that make up the slewing bearing rotate relative to each other, the plastic grease slides in contact with the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, but this sliding is retained by the plastic grease. Therefore, the resistance to relative rotation between the inner ring and the outer ring is not substantially increased.

  In the slewing bearing, a ring gear is formed on the inner surface of the inner ring, and a slewing pinion is engaged with the ring gear. In order to lubricate the meshing portion between the ring gear and the turning pinion, an annular grease bath is formed inside the inner ring. The grease in this grease bath is also used as a supply source for the rolling element housing. As a result, the grease in the space of the rolling element housing portion does not run out of lubrication due to lack of grease even if the lubrication is not performed. However, impurities are mixed in the grease in the grease bath. When the plastic grease is compressed, the grease held in the plastic grease is supplied to the rolling element housing portion, the compression force is released, and when the plastic grease expands, the grease flowing out from the grease bath is absorbed. At this time, a function as a filter for removing impurities in the grease can be exhibited.

  By configuring as described above, it becomes possible to always secure a necessary amount of grease in the rolling element housing portion, and it is not necessary to perform a greasing work for a long period of time, and the contaminated grease is stored in the rolling element housing portion. Intrusion can be prevented and a good lubrication function is always demonstrated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows an overall configuration of a hydraulic excavator as an example of a construction machine to which a turning device is attached. Needless to say, the swivel device of the present invention is not limited to that mounted on a hydraulic excavator.

  In the figure, reference numeral 1 denotes a lower traveling body, 2 denotes an upper turning body, and the upper turning body 2 is connected to the lower traveling body 1 via a turning device 3. In the illustrated embodiment, the lower traveling body 1 includes crawler-type traveling means having a crawler belt. Further, a front work machine 4 as a working means is mounted on the upper swing body 2, and a cab 5 is installed side by side with the front work machine 4. And the building 6 which incorporates equipments, such as an engine, is provided in the rear part position of the cab 5, and the counterweight 7 is installed in the rearmost part position.

  FIG. 2 shows the configuration of the turning device 3. The swivel device 3 includes a swivel bearing 10 and a swivel drive means 20. The slewing bearing 10 has an inner ring 11 and an outer ring 12 each formed in a cylindrical shape, and a rolling element housing portion 13 is formed between the outer peripheral surface of the inner ring 11 and the inner peripheral surface of the outer ring 12. In the rolling element housing portion 13, rolling elements 14 made of steel balls and spacers (not shown) are alternately arranged in the circumferential direction. The inner ring 11 is connected to a round body 15 standing on the center frame of the lower traveling body 1 by bolts, and the outer ring 12 is connected to the floor surface 16 of the upper swing body 2 by bolts.

  The turning drive means 20 has a turning motor 21 installed on the upper turning body 2, and a turning pinion 22 is connected to the output shaft of the turning motor 21. A ring gear 23 is provided on the inner peripheral surface of the inner ring 11, and the turning pinion 22 meshes with the ring gear 23.

  In order to lubricate the meshing portion between the swivel pinion 22 and the ring gear 23, a bus forming wall 24 is attached to the round cylinder 15. The bath forming wall 24 is an inclined wall 24a that rises obliquely upward on the inner peripheral side from the portion where the swivel pinion 22 is disposed, whereby an annular grease bath 25 is formed. The grease is stored up to a predetermined height position. A portion of the bus forming wall 24 inside the inclined wall 24 a forms a horizontal wall portion 24 b at a position close to the floor surface 16 of the upper swing body 2, and grease is interposed between the horizontal wall portion 24 b and the floor surface 16. An annular seal member 26 is attached to seal the bus 25. Further, the central portion of the bus forming wall 24 is opened, and a center joint 27 is attached to the opening. The center joint 27 is for connecting a pipe from a hydraulic pump installed on the upper swing body 2 side to a travel motor constituting a travel drive means in the lower travel body 1.

  In the turning device 3 configured as described above, when the turning motor 21 constituting the turning drive means 20 is driven to rotate the turning pinion 22, the turning pinion 22 is a ring gear of the inner ring 11 constituting the turning bearing 10. Roll along 23. Since the inner ring 11 is provided on the lower traveling body 1 side that is in contact with the ground, the upper revolving body 2 turns together with the outer ring 12. At this time, the rolling element 14 rotates in the rolling element accommodating portion 13, and the inner ring 11 and the outer ring 12 are held in a non-contact state. For this reason, lubrication is performed by covering the entire circumference of the rolling element 14 with an oil film of grease, thereby enabling smooth turning and reducing the load during turning. Further, it is possible to suppress the occurrence of wear at the contact portion between the rolling element 14 and the outer surface of the inner ring 11 and the inner surface of the outer ring 12.

  Thus, in order to reduce the load during turning and to suppress wear, as shown in FIG. 3, grease is sealed in the rolling element housing portion 13, but between the inner ring 11 and the outer ring 12. In order to keep the whole in a non-contact state, open annular gaps 13 a and 13 b are formed above and below the rolling element housing portion 13. Accordingly, the grease is held so as not to flow out of the annular gaps 13a and 13b. For this purpose, a lower annular gap 13b communicating with the rolling element housing portion 13 is fixed to the inner ring 11 side, and a lip-shaped seal member 28 extending in the outer circumferential direction is mounted. As a result, the grease in the rolling element housing portion 13 can be prevented from flowing downward.

  On the other hand, with respect to the annular gap 13a on the upper side of the rolling element housing portion 13, the outer peripheral surface of the inner ring 11 and the inner peripheral surface of the outer ring 12 are tapered surfaces 11a and 12a that are notched obliquely toward the upper end portion. The cross section expands upward in a generally V shape. A plastic grease 30 is attached to the annular gap 13a. The plastic grease 30 has substantially the same shape as the annular gap 13a, and the plastic grease 30 can be easily attached from above the annular gap 13a that is expanded in a V shape. In addition, a pressing plate 31 is detachably mounted on the upper surface of the outer ring 12 in order to fix the plastic grease 30 thus mounted so as not to escape from the annular gap 13a. As shown in FIG. 4, the pressing plate 31 is attached to the upper surface of the plastic grease 30 at about four locations. The pressing plate 31 slightly presses the plastic grease 30 toward the tapered surfaces 11a and 12a. It has become a state. As a result, the plastic grease 30 comes into close contact with the tapered surfaces 11a and 12a.

  Here, as described in the background art section, the plastic grease 30 heats the resin material to the melting temperature or higher in a state where the resin material such as polyethylene and the grease are mixed, and cools the resin material to room temperature. In addition, it is molded so as to have a predetermined shape, and grease is held inside. That is, the plastic grease 30 is a grease carrier. When the resin is compressed, the grease oozes out from the inside, and when the compression force is released to restore the original state, the plastic grease 30 partially expands. Then, grease is sucked from the surroundings.

  By configuring the slewing bearing 10 as described above, an oil film of grease is formed on the entire circumference of the rolling element 14 by the grease sealed in the rolling element housing portion 13, and the relative rotation between the inner ring 11 and the outer ring 12 is performed. Friction at the time is remarkably reduced, turning can be performed smoothly with a light load, and wear of the sliding portions of the rolling elements 14, the inner ring 11 and the outer ring 12 is reduced. The part where the grease is actually required is the part in which the rolling element 14 is mounted inside the rolling element housing part 13. Further, between the inner ring 11 and the outer ring 12, the plastic grease 30 is in contact with the tapered surfaces 11 a and 12 a formed on the upper side thereof, and a pressing force is applied by the action of the holding plate 31. Since the grease is held in the plastic grease 30, sliding between them can be performed smoothly during turning.

  Since the lip-shaped seal member 28 is attached to the lower annular gap 13b formed above and below the rolling element housing portion 13, the grease sealed inside is held and does not flow out. However, since the lip-shaped seal member 28 spans between the inner ring 11 and the outer ring 12 that rotate relative to each other, the grease in the rolling element housing portion 13 gradually leaks over a long period of time. In order to become, it is necessary to replenish grease.

  The plastic grease 30 is a grease carrier, and the resin constituting it is porous, and the grease is held in the gap. At the time of turning, the gap between the inner ring 11 and the outer ring 12 is slightly deformed. Therefore, the plastic grease 30 is compressed and the grease held in the plastic oozes out, and is moved into the rolling element housing portion 13 by the action of gravity. Supplied. On the other hand, at the time of turning, the grease in the grease bath 25 is lifted by meshing of the turning pinion 22 and the ring gear 23, and the upper surface of the plastic grease 30 is covered with the grease. When the plastic grease 30 compressed as described above is restored, the grease is absorbed from the surroundings. At this time, since the plastic grease 30 is wet with the grease from the grease bath 25, the grease is absorbed until it becomes saturated. Since this is repeated when the swivel device 3 is operated, the rolling element housing portion 13 is automatically replenished with grease.

  By the way, although the inside of the grease bath 25 is sealed for the time being, it is not completely sealed. In particular, it is not possible to prevent a slight gap from being generated in the mounting portion of the inner ring 11 and the outer ring 12 and the mounting portion of the turning motor 21. Further, the sealing function of the sealing member 26 interposed between the bus forming wall 24 and the floor surface 16 of the upper swing body 2 deteriorates due to wear for a long period of time. Since construction machines such as hydraulic excavators operate in the outdoors, moist air enters the grease bath 25, and condensation occurs on the bus forming wall 24 and the like due to the temperature difference between the inside and outside of the construction machine. There is a possibility of moisture. Also, rainy water may enter the grease bath 25 during rainy weather. Further, there is a possibility that fine dust may enter, and further generation of wear powder due to the engagement of the swivel pinion 22 and the ring gear 23 and generation of wear powder due to sliding of the seal member 26 cannot be prevented.

  From the above, the grease in the grease bath 25 gradually deteriorates due to impurities being mixed therein. The grease in the grease bath 25 is used to lubricate the meshing portion between the swivel pinion 22 and the ring gear 23. Since the amount of grease in the grease bath 25 is large, some impurities are mixed into the grease. However, the lubricity is not significantly impaired. On the other hand, the lubricity requirement of the contact part between the rolling element 14 and the inner ring 11 and the outer ring 12 in the rolling element housing part 13 is stricter than that of the grease bath 25, and the contact area is also large. Decrease in slidability due to impurities, acceleration of wear due to foreign matters, etc. become more prominent. Therefore, the grease in the grease bath 25 contaminated by impurities and mixed with foreign matters is not directly introduced into the rolling element housing portion 13, but the impurities and foreign matters are removed and grease having good sliding conditions is supplied. .

  Therefore, when the plastic grease 30 is replenished with grease from the grease bath 25 to the rolling element housing portion 13, a function as a filter for removing these impurities, foreign matters and the like is exhibited. That is, the plastic grease 30 is a porous member that can absorb the grease from the outside, but has a large number of minute holes, and wear powder, dust, and the like are taken into the plastic grease 30 from the outside. Can be prevented. Also, the specific gravity difference between water and grease is large, and when the plastic grease 30 absorbs the grease supplied from the grease bath 25, it is from the upper surface side, and the absorption of this grease is slow. Therefore, the oil-water separation is performed when the grease is absorbed, and the absorption of the grease containing moisture into the plastic grease 30 is suppressed as much as possible. That is, the rolling element housing part 13 can be replenished with grease that is fresh or has a low degree of deterioration and good lubrication conditions.

  Further, the grease is scraped up on the plastic grease 30 at the time of turning, and the scraped grease is fluidized due to the occurrence of vibration, the inclination of the vehicle, and the like. Therefore, wear powder, dust, and the like, which are residues separated from the grease by the plastic grease 30, flow out by the flow, and clogging when the plastic grease 30 functions as a filter is prevented.

  As described above, since the rolling element accommodating portion 13 is automatically replenished with good quality grease, the slewing bearing 10 can be smoothly operated without performing complicated greasing work for a long period of time. There is no risk of running out of lubrication.

1 is an overall configuration diagram of a hydraulic excavator as an example of a construction machine to which a turning device of the present invention is attached. It is principal part sectional drawing of the turning apparatus which shows one Embodiment of this invention. It is a principal part enlarged view of FIG. It is a top view which shows a part of slewing bearing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper turning body 3 Turning apparatus 10 Turning bearing 11 Inner ring 12 Outer ring 11a, 12a Tapered surface 13 Rolling body accommodating part 13a, 13b Annular gap 14 Rolling body 16 Floor surface 20 Turning apparatus 21 Turning motor 22 Turning pinion 23 Ring gear 24 Bus forming wall 25 Grease bath 30 Plastic grease 31 Presser plate

Claims (3)

Turning having an orbiting rolling element housing portion between the inner ring and the outer ring, having a swivel bearing in which a predetermined number of rolling elements and spacers are alternately arranged in the rolling element housing portion, and in which a lubricant is enclosed In the device
Between the inner ring and the outer ring, an annular seal member that seals the lower part of the rolling element housing portion is mounted on the lower side, and an annular plastic grease is mounted on the upper side. A swivel device. A ring gear is formed on the inner surface of the inner ring, and the ring gear is configured to mesh with the turning pinion. In order to supply grease to the meshing portion of the ring gear and the turning pinion, a circle is formed inside the inner ring. An annular grease bath is formed, and the plastic grease is mounted so as to be in close contact with the inner ring and the outer ring, and the grease from the grease bath is replenished to the rolling element housing portion through the plastic grease. The swivel device according to claim 1. The plastic grease mounting portion in the inner ring and the outer ring is formed by a tapered surface that expands toward the upper end side, and a pressing member that presses the plastic grease against the tapered surface is provided. The swivel device according to claim 1.

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